Reservoir pressure system for medicament inhaler

ABSTRACT

An inhaler includes an accurate and consistent mechanical dose metering system that dispenses dry powdered medicament in discrete amounts or doses for patient inhalation, a pressure relief system that manages pressure within a medicament reservoir of the inhaler to ensure consistently dispensed doses, and a dose counting system indicating the number of doses dispensed by or remaining in the inhaler.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.09/888,199, filed on Jun. 23, 2001, now U.S. Pat. No. 7,540,282, andclaims the benefit of the filing dates of U.S. Provisional ApplicationNos. 60/213,668, filed Jun. 23, 2000, and 60/213,382, filed Jun. 23,2000. The disclosures of all of these applications are herebyincorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to an apparatus and method foradministering medicament for inhalation by a patient and, moreparticularly, to a dry powdered medicament inhaler.

BACKGROUND OF THE INVENTION

Metered dose medicament inhalers are well known for dispensingmedicament to the lungs of a patient, for treating asthma for example.Existing types of medicament dispensing inhalers include pressurizedpropellant inhalers, aqueous solution inhalers, and dry-powderedinhalers.

U.S. Pat. No. 5,503,144 to Bacon, for example, shows a dry powderedinhaler. The inhaler includes a reservoir for containing a dry powderedmedicament, a metering chamber for removal of the powdered medicamentfrom the reservoir in discrete amounts, and an air inlet for entrainingthe removed powdered medicament through a mouthpiece upon patientinhalation.

Another example is U.S. Pat. No. 5,971,951 to Ruskewicz, which shows aninhaler including a motor driven cam mechanism for extruding aqueousmedicament through a porous membrane to form a medicament aerosol forinhalation by a patient. The inhaler also includes sensors, circuitryand a microprocessor that determines the rate of patient inhalation andoperates the extrusion mechanism only upon adequate inhalation levels.

A pressurized propellant, or “aerosol” inhaler is shown in U.S. Pat. No.5,447,150 to Bacon, which also discloses a simple, mechanical actuationassembly for ensuring that medicament is dispensed from the inhaler onlyupon adequate inhalation by a patient. The actuation assembly works byapplying a pre-load to a valve of the aerosol container sufficient tocause a dose release, but prevents the release by applying a pneumaticresisting force. The dose of medicament is then released upon a patientinhalation strong enough to move a door within the assembly, which inturn releases the pneumatic resisting force.

What is still desired, however, is a new and improved inhaler foradministering medicament for patient inhalation. Preferably, the new andimproved inhaler can be used with dry powdered medicament. In addition,the new and improved inhaler will preferably include mechanicalassemblies for metering doses of medicament, managing medicamentreservoir pressure, and counting the number of doses remaining in theinhaler.

SUMMARY OF THE INVENTION

The present disclosure, therefore, provides a new and improvedmedicament inhaler having a unique dose metering system. The inhalerincludes a mouthpiece for patient inhalation, a delivery passageway fordirecting an inhalation induced air flow through the mouthpiece, achannel extending from the delivery passageway, and a reservoir forcontaining medicament, with the reservoir having a dispenser portconnected to the channel. In a preferred form, the dose metering systemincludes a cup received in the channel, which is movable between thedispenser port and the delivery passageway, a cup spring biasing the cuptowards one of the dispenser port and the passageway, and a yoke movablebetween at least two positions. The yoke includes a ratchet engaging thecup and preventing movement of the cup when the yoke is in one of thepositions, and allowing movement of the cup when the yoke is in anotherof the positions.

The present disclosure also provides a medicament inhaler having aunique reservoir pressure system. The inhaler includes a sealedreservoir having a dispenser port, and a channel communicating with thedispenser port, and a cup assembly movably received in the channel. In apreferred form, the pressure system includes a pressure relief port inthe channel, and a conduit providing fluid communication between aninterior of the sealed reservoir and the pressure relief port of thechannel. The cup assembly includes a recess adapted to receivemedicament when aligned with the dispenser port, a first sealing surfaceadapted to seal the dispenser port when the recess is unaligned with thedispenser port, and a second sealing surface adapted to seal thepressure relief port when the recess is aligned with the dispenser portand unseal the pressure relief port when the recess is unaligned withthe dispenser port.

The present disclosure additionally provides a medicament inhaler havinga unique dose counter. The inhaler includes a mouthpiece for patientinhalation, a dose metering system including a pawl movable along apredetermined path during the metering of a dose of medicament to themouthpiece by the dose metering system, and a dose counter. In apreferred form, the dose counter includes a bobbin, a rotatable spool,and a rolled ribbon received on the bobbin, rotatable about an axis ofthe bobbin. The ribbon has indicia thereon successively extendingbetween a first end of the ribbon secured to the spool and a second endof the ribbon positioned on the bobbin. The dose counter also includesteeth extending radially outwardly from the spool into the predeterminedpath of the pawl so that the spool is rotated by the pawl and the ribbonadvanced onto the spool during the metering of a dose to the mouthpiece.

Thus, the present disclosure provides a new and improved inhalerincluding a simple, accurate and consistent mechanical dose meteringsystem that dispenses dry powdered medicament in discrete amounts ordoses for patient inhalation, a reservoir pressure system that ensuresconsistently dispensed doses, and a dose counter indicating the numberof doses remaining in the inhaler.

Further features and advantages of the presently disclosed inhaler willbecome more readily apparent to those having ordinary skill in the artto which the present disclosure relates from the drawings and thedetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art will more readilyunderstand how to construct a dry powdered medicament inhaler inaccordance with the present disclosure, a preferred embodiment isdescribed below with reference to the drawing figures wherein:

FIG. 1 is a first side isometric view of a dry powdered medicamentinhaler according to the present disclosure;

FIG. 2 is an exploded, second side isometric view of the inhaler of FIG.1;

FIG. 3 is a second side isometric view of a main assembly of the inhalerof FIG. 1;

FIG. 4 is a second side isometric view of the main assembly of theinhaler of FIG. 1, shown with a yoke removed;

FIG. 5 is an exploded first side isometric view of the main assembly ofthe inhaler of FIG. 1;

FIG. 6 is an exploded enlarged isometric view of a medicament cup of theinhaler of FIG. 1;

FIG. 7 is an exploded first side isometric view of a hopper and ade-agglomerator of the inhaler of FIG. 1;

FIG. 8 is an exploded second side isometric view of the hopper and aswirl chamber roof of the de-agglomerator of the inhaler of FIG. 1;

FIG. 9 is an exploded first side isometric view of a case, cams and amouthpiece cover of the inhaler of FIG. 1;

FIG. 10 is an enlarged side isometric view of one of the cams of theinhaler of FIG. 1;

FIG. 11 is a second side isometric view of the yoke of the inhaler ofFIG. 1;

FIG. 12 is a first side isometric view of the yoke of the inhaler ofFIG. 1, showing a ratchet and a push bar of the yoke;

FIG. 13 is a schematic illustration of lateral movement of a boss of themedicament cup in response to longitudinal movement of the ratchet andthe push bar of the yoke of the inhaler of FIG. 1;

FIG. 14 is an enlarged isometric view of a dose counter of the inhalerof FIG. 1;

FIG. 15 is an exploded enlarged isometric view of the dose counter ofthe inhaler of FIG. 1; and

FIG. 16 is an enlarged isometric view, partially in section, of aportion of the inhaler of FIG. 1 illustrating medicament inhalationthrough the inhaler.

Like reference characters designate identical or correspondingcomponents and units throughout the several views.

DETAILED DESCRIPTION

Referring to FIGS. 1 through 16, the present disclosure provides a newand improved inhaler 10 for dispensing a dry-powdered medicament inmetered doses for patient inhalation. The inhaler 10 of the presentdisclosure provides many beneficial features including but not limitedto a dose metering system that dispenses dry powdered medicament indiscrete amounts or doses for patient inhalation, a medicament reservoirpressure system for managing pressure within the reservoir, and a dosecounting system indicating the number of doses remaining in the inhaler10.

The inhaler 10 generally includes a housing 18, and an assembly 12received in the housing (see FIG. 2). The housing 18 includes a case 20having an open end 22 and a mouthpiece 24 for patient inhalation, a cap26 secured to and closing the open end 22 of the case 20, and a cover 28pivotally mounted to the case 20 for covering the mouthpiece 24 (seeFIGS. 1, 2 and 9). The housing 18 is preferably manufactured from aplastic such as polypropylene, acetal or moulded polystyrene, but may bemanufactured from metal or another suitable material.

The internal assembly 12 includes a reservoir 14 for containing drypowered medicament in bulk form, a de-agglomerator 32 that breaks downthe medicament between a delivery passageway 34 and the mouthpiece 24,and a spacer 38 connecting the reservoir to the de-agglomerator.

Reservoir

The reservoir 14 is generally made up of a collapsible bellows 40 and ahopper 42 having a dispenser port 44 (see FIGS. 2-5 and 7-8) fordispensing medicament upon the bellows 40 being at least partiallycollapsed to reduce the internal volume of the reservoir. The hopper 42is for holding the dry powder medicament in bulk form and has an openend 46 closed by the flexible accordion-like bellows 40 in asubstantially air-tight manner. An air filter 48 covers the open end 46of the hopper 42 and prevents dry powder medicament from leaking fromthe hopper 42 (see FIG. 7).

Spacer

A base 50 of the hopper 42 is secured to a spacer 38, which is in turnsecured to the de-agglomerator 32 (see FIGS. 3-5 and 7-8). The hopper42, the spacer 38, and the de-agglomerator 32 are preferablymanufactured from a plastic such as polypropylene, acetal or mouldedpolystyrene, but may be manufactured from metal or another suitablematerial. The hopper 42, the spacer 38 and the de-agglomerator 32 areconnected in a manner that provides an air tight seal between the parts.For this purpose heat or cold sealing, laser welding or ultrasonicwelding could be used, for example.

The spacer 38 and the hopper 42 together define the medicament deliverypassageway 34, which preferably includes a venturi 36 (see FIG. 16) forcreating an entraining air flow. The spacer 38 defines a slide channel52 communicating with the dispenser port 44 of the hopper 42, and achimney 54 providing fluid communication between the medicament deliverypassageway 34 and a supply port 56 of the de-agglomerator 32 (see FIGS.7 and 8). The slide channel 52 extends generally normal with respect tothe axis “A” of the inhaler 10.

De-Agglomerator

As its name implies, the de-agglomerator 32 breaks down agglomerates ofdry powder medicament before the dry powder leaves the inhaler 10through the mouthpiece 24. The de-agglomerator includes a swirl chamber58 extending from the supply port 56 to an outlet port 60 connected tothe mouthpiece 24 (see FIG. 16). The de-agglomerator 32 also includestwo diametrically opposed inlet ports 62 that extend substantiallytangential to the circular cross-section of the swirl chamber. Radialvanes 64 are positioned at the top of the swirl chamber and are sizedsuch that at least a portion of breath-actuated air streams enteringthrough the diametrically opposed inlet ports 62 collide with the vanes.

The inhaler 10 preferably includes a de-agglomerator of the typedisclosed in co-pending provisional U.S. patent application Ser. No.60/213,382, filed Jun. 23, 2000 (entitled “De-Agglomerator forBreath-Actuated Dry Powder Inhaler”), which has been incorporated hereinby reference. It should be understood that although the inhaler 10 ofthe present disclosure is shown with a particular de-agglomerator 32,the inhaler 10 is not limited to use with the de-agglomerator shown andcan be used with other types of de-agglomerators or a simple swirlchamber.

Dose Metering System

The dose metering system includes a first yoke 66 and a second yoke 68mounted on the internal assembly 12 within the housing 18, and movablein a linear direction parallel with an axis “A” of the inhaler 10 (seeFIG. 2). An actuation spring 69 is positioned between the cap 26 of thehousing 18 and the first yoke 66 for biasing the yokes in a firstdirection towards the mouthpiece 24. In particular, the actuation spring69 biases the first yoke 66 against the bellows 40 and the second yoke68 against cams 70 mounted on the mouthpiece cover 28 (see FIG. 9).

The first yoke 66 includes an opening 72 that receives and retains acrown 74 of the bellows 40 such that the first yoke 66 pulls and expandsthe bellows 40 when moved towards the cap 26, i.e., against theactuation spring 69 (see FIG. 2). The second yoke 68 includes a belt 76,which receives the first yoke 66, and two cam followers 78 extendingfrom the belt in a direction opposite the first yoke 66 (see FIGS. 3, 11and 12), towards the cams 70 of the mouthpiece cover 28.

The dose metering system also includes the two cams 70 mounted on themouthpiece cover 28 (see FIGS. 9 and 10), and movable with the cover 28between open and closed positions. The cams 70 each include an opening80 for allowing outwardly extending hinges 82 of the case 20 to passtherethrough and to be received in first recesses 84 of the cover 28.The cams 70 also include bosses 86 extending outwardly and received insecond recesses 88 of the cover 28, such that the cover 28 pivots aboutthe hinges 82 and the cams 70 move with the cover 28 about the hinges.

Each cam 70 also includes first, second and third cam surfaces 90, 92,94, and the cam followers 78 of the second yoke 68 are biased againstthe cam surfaces by the actuation spring 69. The cam surfaces 90, 92, 94are arranged such that the cam followers 78 successively engage thefirst cam surfaces 90 when the cover 28 is closed, the second camsurfaces 92 when the cover 28 is partially opened, and the third camsurfaces 94 when the cover 28 is fully opened. The first cam surfaces 90are spaced further from the hinges 82 than the second and the third camsurfaces, while the second cam surfaces 92 are spaced further from thehinges 82 than the third cam surfaces 94. The cams 70, therefore, allowthe yokes 66, 68 to be moved by the actuation spring 69 parallel withthe axis “A” of the inhaler 10 in the first direction (towards themouthpiece 24) through first, second and third positions as the cover 28is opened. The cams 70 also push the yokes 66, 68 in a second directionparallel with the axis “A” (against the actuation spring 69 and towardsthe cap 26 of the housing 18) through the third, the second and thefirst positions as the cover 28 is closed.

The dose metering system further includes a cup assembly 96 movablebetween the dispenser port 44 of the reservoir 14 and the deliverypassageway 34. The cup assembly 96 includes a medicament cup 98 mountedin a sled 100 slidably received in the slide channel 52 of the spacer 38below the hopper 42 (see FIGS. 5 and 6). The medicament cup 98 includesa recess 102 adapted to receive medicament from the dispenser port 44 ofthe reservoir 14 and sized to hold a predetermined dose of dry powderedmedicament when filled. The cup sled 100 is biased along the slidechannel 52 from the dispenser port 44 of the hopper 42 towards thedelivery passageway 34 by a cup spring 104, which is secured on thehopper 42 (see FIGS. 4 and 5).

The dose metering system also includes a ratchet 106 and a push bar 108on one of the cam followers 78 of the second yoke 68 that engage a boss110 of the cup sled 100 (see FIGS. 5, 11 and 12). The ratchet 106 ismounted on a flexible flap 112 and is shaped to allow the boss 110 ofthe sled 100 to depress and pass over the ratchet 106, when the boss 110is engaged by the push bar 108. Operation of the dose metering system isdiscussed below.

Reservoir Pressure System

The reservoir pressure system includes a pressure relief conduit 114 influid communication with the interior of the reservoir 14 (see FIGS. 7and 8), and a pressure relief port 116 in a wall of the slide channel 52(see FIGS. 5 and 8) providing fluid communication with the pressurerelief conduit 114 of the hopper 42.

The medicament cup assembly 96 includes a first sealing surface 118adapted to seal the dispenser port 44 upon the cup assembly being movedto the delivery passageway 34 (see FIGS. 5 and 6). A sealing spring 120is provided between the sled 100 and the cup 98 for biasing themedicament cup 98 against a bottom surface of the hopper 42 to seal thedispenser port 44 of the reservoir 14. The cup 98 includes clips 122that allow the cup to be biased against the reservoir, yet retain thecup in the sled 100.

The sled 100 includes a second sealing surface 124 adapted to seal thepressure relief port 116 when the recess 102 of the cup 98 is alignedwith the dispenser port 44, and an indentation 126 (see FIG. 6) adaptedto unseal the pressure relief port 116 when the first sealing surface118 is aligned with the dispenser port 44. Operation of the pressuresystem is discussed below.

Dose Counting System

The dose counting system 16 is mounted to the hopper 42 and includes aribbon 128, having successive numbers or other suitable indicia printedthereon, in alignment with a transparent window 130 provided in thehousing 18 (see FIG. 2). The dose counting system 16 includes arotatable bobbin 132, an indexing spool 134 rotatable in a singledirection, and the ribbon 128 rolled and received on the bobbin 132 andhaving a first end 127 secured to the spool 134, wherein the ribbon 128unrolls from the bobbin 132 so that the indicia is successivelydisplayed as the spool 134 is rotated or advanced.

The spool 134 is arranged to rotate upon movement of the yokes 66, 68 toeffect delivery of a dose of medicament from the reservoir 14 into thedelivery passageway 34, such that the number on the ribbon 128 isadvanced to indicate that another dose has been dispensed by the inhaler10. The ribbon 128 can be arranged such that the numbers, or othersuitable indicia, increase or decrease upon rotation of the spool 134.For example, the ribbon 128 can be arranged such that the numbers, orother suitable indicia, decrease upon rotation of the spool 134 toindicate the number of doses remaining in the inhaler 10. Alternatively,the ribbon 128 can be arranged such that the numbers, or other suitableindicia, increase upon rotation of the spool 134 to indicate the numberof doses dispensed by the inhaler 10.

The indexing spool 134 preferably includes radially extending teeth 136,which are engaged by a pawl 138 extending from one of the cam followers78 (see FIGS. 3 and 11) of the second yoke 68 upon movement of the yoketo rotate, or advance, the indexing spool 134. More particularly, thepawl 138 is shaped and arranged such that it engages the teeth 136 andadvances the indexing spool 134 only upon the mouthpiece cover 28 beingclosed and the yokes 66, 68 moved back towards the cap 26 of the housing18.

The dose counting system 16 also includes a chassis 140 that secures thedose counting system to the hopper 42 and includes shafts 142, 144 forreceiving the bobbin 132 and the indexing spool 134. The bobbin shaft142 is preferably forked and includes radial nubs 146 for creating aresilient resistance to rotation of the bobbin 132 on the shaft 142. Aclutch spring 148 is received on the end of the indexing spool 134 andlocked to the chassis 140 to allow rotation of the spool 134 in only asingle direction (counter-clockwise as shown in FIG. 14). Operation ofthe dose counting system 16 is discussed below.

Operation

FIG. 13 illustrates the relative movements of the boss 110 of the cupsled 100, and the ratchet 106 and the push bar 108 of the second yoke 68as the mouthpiece cover 28 is opened and closed. In the first positionof the yokes 66, 68 (wherein the cover 28 is closed and the camfollowers 78 are in contact with the first cam surfaces 90 of the cams70), the ratchet 106 prevents the cup spring 104 from moving the cupsled 100 to the delivery passageway 34. The dose metering system isarranged such that when the yokes are in the first position, the recess102 of the medicament cup 98 is directly aligned with the dispenser port44 of the reservoir 14 and the pressure relief port 116 of the spacer 38is sealed by the second sealing surface 124 of the cup sled 100.

Upon the cover 28 being partially opened such that the second camsurfaces 92 of the cams 70 engage the cam followers 78, the actuatorspring 69 is allowed to move the yokes 66, 68 linearly towards themouthpiece 24 to the second position and partially collapse the bellows40 of the medicament reservoir 14. The partially collapsed bellows 40pressurizes the interior of the reservoir 14 and ensures medicamentdispensed from the dispenser port 44 of the reservoir fills the recess102 of the medicament cup 98 such that a predetermined dose is provided.In the second position, however, the ratchet 106 prevents the cup sled100 from being moved to the delivery passageway 34, such that the recess102 of the medicament cup 98 remains aligned with the dispenser port 44of the reservoir 14 and the pressure relief port 116 of the spacer 38remains sealed by the second sealing surface 124 of the cup assembly 96.

Upon the cover 28 being fully opened such that the third cam surfaces 94engage the cam followers 78, the actuator spring 69 is allowed to movethe yokes 66, 68 further towards the mouthpiece 24 to the thirdposition. When moved to the third position, the ratchet 106 disengages,or falls below the boss 110 of the cup sled 100 and allows the cup sled100 to be moved by the cup spring 104, such that the filled recess 102of the cup 98 is positioned in the venturi 36 of the delivery passageway34 and the dispenser port 44 of the reservoir 14 is sealed by the firstsealing surface 118 of the cup assembly 96. In addition, the pressurerelief port 116 is uncovered by the indentation 126 in the side surfaceof the sled 100 to release pressure from the reservoir 14 and allow thebellows 40 to further collapse and accommodate the movement of the yokes66, 68 to the third position. The inhaler 10 is then ready forinhalation by a patient of the dose of medicament placed in the deliverypassageway 34.

As shown in FIG. 16, a breath-induced air stream 150 diverted throughthe delivery passageway 34 passes through the venturi 36, entrains themedicament and carries the medicament into the de-agglomerator 32 of theinhaler 10. Two other breath-induced air streams 152 (only one shown)enter the de-agglomerator 32 through the diametrically opposed inletports 62 and combine with the medicament entrained air stream 150 fromthe delivery passageway 34. The combined flows 154 and entrained drypowder medicament then travel to the outlet port 60 of thede-agglomerator and pass through the mouthpiece 24 for patientinhalation.

Once inhalation is completed, the mouthpiece cover 28 can be closed.When the cover 28 is closed, the trigger cams 70 force the yokes 66, 68upwardly such that the first yoke 66 expands the bellows 40, and thepawl 138 of the second yoke 68 advances the indexing spool 134 of thedose counting system 16 to provide a visual indication of a dose havingbeen dispensed. In addition, the cup assembly 96 is forced back to thefirst position by the pusher bar 108 of the upwardly moving second yoke68 (see FIG. 13) such that the boss 110 of the cup sled 100 is engagedand retained by the ratchet 106 of the second yoke 68.

It should be understood that the foregoing detailed description andpreferred embodiment are only illustrative of inhalers constructed inaccordance with the present disclosure. Various alternatives andmodifications to the presently disclosed inhalers can be devised bythose skilled in the art without departing from the spirit and scope ofthe present disclosure. For example, the medicament cup could beprovided on a rotary sled, advanced by movement of the yokes. Inaddition, the outlet port of the pressure relief could be provided inlocations other than the side wall of the slide channel. Furthermore,the dose counting system could be adapted to provide an audibleindication in addition to a visual indication of a dispensed dose.Accordingly, the present disclosure is intended to embrace all suchalternatives and modifications that fall within the spirit and scope ofan inhaler as recited in the appended claims.

1. A medicament inhaler, comprising: a mouthpiece for patientinhalation; a delivery passageway for directing an inhalation inducedair flow through the mouthpiece; a channel extending from the deliverypassageway; a reservoir for containing medicament, the reservoir havinga dispensing port connected to the channel; a cup received in thechannel and movable between the dispensing port and the deliverypassageway; a cup spring biasing the cup either towards the deliverypassageway and away from the dispensing port or towards the dispensingport and away from the delivery passageway; and a yoke movable betweenat least two positions and including a ratchet operatively engaging thecup and preventing movement of the cup when the yoke is in one of thepositions and allowing movement of the cup when the yoke is in anotherof the positions.
 2. An inhaler according to claim 1, wherein the cupspring biases the cup from the dispensing port and towards the deliverypassageway.
 3. An inhaler according to claim 2, wherein the yoke furtherincludes a push bar adapted to return the cup to the dispensing port ofthe reservoir upon movement of the yoke from the another position to theone position.
 4. An inhaler according to claim 3, further comprising: atleast one movable cam including at least two successive cam surfaces;and a spring biasing the yoke against the cam such that movement of thecam causes the yoke to successively engage the cam surfaces and move theyoke between the at least two positions.
 5. An inhaler according toclaim 4, wherein the cam includes three successive cam surfaces formoving the yoke between first, second and third positions, the ratchetbeing adapted to prevent movement of the cup to the passageway when theyoke is in the first and second positions and to allow movement of thecup to the passageway when the yoke is in the third position, and thepush bar being adapted to return the cup to the dispensing port of thereservoir upon movement of the yoke to the first position.
 6. An inhaleraccording to claim 5, further comprising a cover movable to open andclose the mouthpiece, the cam being secured to the cover for movementtherewith, whereby moving the cover to open and close the mouthpiececauses the yoke to move between the first, second and third positions.7. An inhaler according to claim 4, wherein the cam is movable byrotation.
 8. An inhaler according to claim 1, wherein the reservoirincludes a volume of dry powdered medicament.
 9. An inhaler according toclaim 1, further comprising a de-agglomerator between the deliverypassageway and the mouthpiece.
 10. An inhaler according to claim 1,further comprising: a pawl extending from the yoke; a dose counterincluding a bobbin, a rotatable spool, a rolled ribbon received on thebobbin and rotatable about an axis of the bobbin, the ribbon havingindicia thereon successively extending between a first end of the ribbonsecured to the spool and a second end of the ribbon positioned on thebobbin, and teeth extending radially outward from the spool into apredetermined path of the pawl during movement of the yoke between theat least two positions so that the spool is rotated by the pawl and theribbon is advanced onto the spool during movement of the cup between thedispensing port and the delivery passageway.
 11. An inhaler according toclaim 1, wherein the channel includes a pressure relief port, theinhaler further comprising: a conduit providing fluid communicationbetween an interior of the reservoir and the pressure relief port;wherein the cup includes a recess adapted to receive medicament whenaligned with the dispensing port of the reservoir, a first sealingsurface adapted to seal the dispensing port when the recess is notaligned with the dispensing port, and a second sealing surface adaptedto seal the pressure relief port when the recess is aligned with thedispensing port and to unseal the pressure relief port when the recessis not aligned with the dispensing port.
 12. A medicament inhaler,comprising: a mouthpiece for patient inhalation; a delivery passagewayfor directing an inhalation induced air flow through the mouthpiece; achannel extending from the delivery passageway; a reservoir forcontaining medicament, the reservoir having a dispensing port connectedto the channel; a cup received in the channel and movable between thedispensing port and the delivery passageway; a cup spring biasing thecup either towards the delivery passageway and away from the dispensingport or towards the dispensing port and away from the deliverypassageway; a yoke movable between at least two positions and includinga ratchet operatively engaging the cup and preventing movement of thecup when the yoke is in one of the positions and allowing movement ofthe cup when the yoke is in another of the positions; at least onemovable cam including at least two successive cam surfaces; and a springbiasing the yoke against the cam such that movement of the cam causesthe yoke to successively engage the cam surfaces and move the yokebetween the at least two positions.
 13. A medicament inhaler,comprising: a mouthpiece for patient inhalation; a delivery passagewayfor directing an inhalation induced air flow through the mouthpiece; achannel extending from the delivery passageway; a reservoir forcontaining medicament, the reservoir having a dispensing port connectedto the channel; a cup received in the channel and movable between thedispensing port and the delivery passageway; a cup spring biasing thecup either towards the delivery passageway and away from the dispensingport or towards the dispensing port and away from the deliverypassageway; a yoke movable between at least two positions and includinga ratchet operatively engaging the cup and preventing movement of thecup when the yoke is in one of the positions and allowing movement ofthe cup when the yoke is in another of the positions; and ade-agglomerator between the delivery passageway and the mouthpiece.